01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan or line with parchment paper.
02 - In a medium bowl, whisk together flour, baking soda, and salt. Set aside.
03 - In a large bowl, mix melted butter, brown sugar, and granulated sugar until smooth.
04 - Beat in eggs one at a time, then stir in vanilla extract.
05 - Gradually fold in the dry ingredients until just combined; do not overmix.
06 - Stir in chocolate chips and nuts (if using).
07 - Spread dough evenly into the prepared pan.
08 - Bake for 23-27 minutes, or until golden brown and a toothpick inserted in the center comes out with a few moist crumbs.
09 - Cool completely in the pan on a wire rack before cutting into bars.